1. Field of the Invention
The present invention relates to an object tracking method, and more particularly, to an illumination-invariant object tracking method, and an image editing system using the method.
2. Description of the Related Art
The present trend toward the introduction of “multimedia” into almost all information provisions and flows has resulted in a variety of digital cameras, video conferencing cameras, video image processing systems for processing an image taken from a camera, and software therefor released in the market.
An image editing system for editing a moving picture taken by a camera has a variety of functions of processing an image of a specific person's face or product in a frame, for example, as a mosaic. Among the variety of functions of the image editing system, the mosaic processing function can be performed on the entire frame or a particular region of a frame. As disclosed in Korean Patent No. 10-170698 entitled “Real-time Image Mosaic System”, having an applicant in common with the present invention, the mosaic processing function can be performed in real time based on the motion of an image of concern.
In general, most images are taken in inconstant illumination conditions by a camera. Specifically, when taking pictures outdoors, variable natural light intensities/or spectrums result in images whose brightness/or color is not uniform. In this case, if a mosaic process is performed irrespective of the intensity variation, due to brightness/or color-dependant variations in pixel values of the image, the mosaic process may be performed inaccurately. To solve this problem, a mosaic processing method using a tracking algorithm based on the shape information of an object was suggested. However, this method increases complexity, and thus needs a high-performing computing system and memory. Furthermore, the method cannot be applied to real-time processing.